In the short term, removing the flag entirely is fine. The original justification was that synfig needed speed more than precision.
I've noticed some weirdness on the darwin-powerpc platform when using -ffast-math. Probably related. On Jun 14, 2006, at 9:27 AM, Paul Wise wrote: > Hi all, > > In addition to vorlon's comments on this debian bug: > > http://bugs.debian.org/367048 > > I got these comments on IRC: > > <pabs> vorlon: are there any other platforms than alpha where > -ffast-math is known to break code? > <Sesse> pabs: -ffast-math can break code easily > <ifvoid> pabs: many code is broken by -ffast-math > <Sesse> that's why it's not part of any -O option > <ifvoid> it used to break mozilla, for exmaple > <ifvoid> (not sure if it still does) > <pabs> so, to be avoided everywhere? > <ifvoid> pabs: except for very specialized apps, yes > <ifvoid> I tend to use it for my numerical progs > <ifvoid> it's really only useful if you have to do many cos() or pow() > or so > <pabs> hmm, I wonder if a complex 2D animation renderer counts > (http://www.synfig.com) > <ifvoid> and if you don't care about range checking > <pabs> I shall talk to upstream, thanks all > <ifvoid> I usually disable it in any package builds > <mrvn> doesn't -ffast-math only circumvent the extra redirection for > libm calls? > <Sesse> mrvn: no > <ifvoid> mrvn: it disables range checking > <ifvoid> for negative input of log(), for example > <ifvoid> and disables checking for inf and nan and such things > <mrvn> on cpus that don't have that in hardware > <Sesse> ifvoid: it also replaces functions with odd macros > <Sesse> ifvoid: some of which have reduced argument range and > precision > <pabs> Sesse/ifvoid/mrvn: mind if I paste this stuff to my upstream? > <ifvoid> pabs: go ahead > <ifvoid> pabs: the gcc info page is pretty informative, too > <ifvoid> sec 3.10 > <Sesse> pabs: np > > darco: > > * is there a reason -ffast-math is used by default in synfig? > * if it is, any ideas about how to disable it on some platforms? > linux-alpha being one of them. > > -- > bye, > pabs > > http://wiki.debian.org/PaulWise _______________________________________________ Synfig-devl mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/synfig-devl
